The central premise of this proposal is that functional biomedical sensing devices must directly interface to the molecular-scale processes of biology. These devices must extract and process information from a complex environment of interacting non-linear biomolecular processes and, in an ideal embodiment, intervene in processes gone awry. Functionality at this level of complexity requires engineering of functional nanoscale components within microscale structures. Further, we must employ processing schemes that are highly complex yet can be implemented in a very small volume. Nature's answer to this design challenge is the cell, and the objective of this work is to develop sensors that mimic the dimensions and some portion of the functionality of a cell. Only by mimicking cellular features will effective operation and interfacing to biological systems be achieved. To achieve this ideal, we will exploit recent advances in nanofabrication that allow for the synthesis of physical features on length scales ranging from nanometers to centimeters. These fabrication techniques will allow for the construction of cellular mimetics that incorporate features such as semi-permeable membranes, chemical sensors and chemical actuators in a footprint of less than 100 um. The nanostructured features will be derived from the synthesis of carbon nanofibers that will allow for control on the molecular scale. We will establish the functional elements of a cellular mimic and integrate these capabilities for demonstrations of sensing and actuation at the molecular and cellular scale.